1. Field of the Invention
This invention relates generally to medical devices used during surgery, including inflatable thermal blankets and surgical drapes. More particularly, the invention pertains to a surgical barrier device that incorporates an inflatable thermal blanket to control patient body temperature during a medical procedure such as surgery, and a surgical drape that provides a barrier between a surgical field and one or more other fields during surgery, while providing access to the surgical field.
2. Description of the Related Art
The inflatable thermal blanket prior art is well described in prior U.S. Pat. No. 4,572,188 entitled "AIRFLOW COVER FOR CONTROLLING BODY TEMPERATURE," and prior U.S. Pat. No. 5,620,482 entitled "INFLATABLE THERMAL BLANKET WITH A FOOT DRAPE". In these prior patents, an inflatable thermal blanket is placed over a patient and inflated by a thermally-controlled inflating medium, such as warmed air. The pressure of the inflating medium causes the blanket to expel the warmed air through holes in the underside of the blanket, thereby creating an ambient environment about the patient, the thermal characteristics of which are determined by the temperature of the inflating medium. The holes open through a blanket base sheet into the interior of the blanket. Such an inflatable thermal blanket is intended, among other things, for the treatment or prevention of hypothermia, as might occur intraoperatively, or postoperatively.
Evaluation of the inflatable thermal blanket by skilled practitioners has resulted in general approbation: the opinion is that an inflatable thermal blanket efficiently and effectively treats hypothermia. However, while the prior art inflatable thermal blanket achieves its objective, certain improvements to it have been desirable in order to realize additional clinical objectives and to enjoy further advantages in its use during surgery. For example, the preferred use for a inflatable thermal blanket is patient temperature management, by which a patient's temperature is controlled by distributing thermally-controlled air over the patient's body. For this purpose, an inflatable thermal blanket is deployed to cover all, or a portion of, the patient's body; in addition, it may include means to access the patient, for surgery, while lying over the patient and providing temperature regulation. However, such coverage does not always provide a complete barrier between the surgical site and the patient.
A surgical drape is the usual means employed for provision of a barrier between a surgical site and other fields, during surgery. Relatedly, a surgical drape is employed for such purposes as keeping fluids confined to the surgical site, maintaining sterility of the surgical site, and screening the anesthesia work area. Attempts have been made to incorporate some functions of a surgical drape into certain elements of inflatable thermal blankets. One example of incorporation of barrier functions into an inflatable thermal blankets is found in U.S. Pat. No. 5,545,194, in which a portion of an inflatable thermal blanket is maintained, uninflated, while surgery is performed on a patient, and then is deployed and inflated over the surgical site. In U.S. Pat. No. 5,336,250, transparent uninflatable sheets at one end of an inflatable thermal blanket provide viewing of portions of a patient's body during medical treatment. In U.S. Pat. No. 5,300,101, plastic sheets with adhesive strips seal off a surgical site from a flow of warm air emitted by an inflatable thermal blanket.
One difficulty in providing access to a surgical site, or to other areas of a patient, during surgery, through an inflatable thermal blanket utilizing superatmospheric, temperature-controlled air is that the openings formed in the blanket to provide access may permit the temperature-regulated air to escape, thereby decreasing the thermal regulation achieved by use of the blanket.
Further, the draping functions achieved by the prior art uninflatable drapes that are provided as extensions of inflatable thermal blanket structures are limited. They are primarily used for localized entrapment of warmed air, and to limit sealing between the flow of warmed air and a surgical site. These are well short of all of the functions required of a surgical drape. Therefore, a need exists for a device that combines an inflatable thermal blanket that is capable of delivering a temperature controlled airflow to a patient in order to manage the patient's body temperature during surgery, while simultaneously providing a barrier between a surgical site and other areas and allowing access to the patient.